The William Root House, one of the oldest remaining homes in the Atlanta area, was built about 1845 for Hannah and William Root, early settlers of Marietta. William Root, born in Philadelphia in 1815, moved to Marietta in August 1839 to open a drug and mercantile store, becoming one of the town's earliest merchants and first druggist. He married Hannah Remer Simpson a year later, and in 1844 they bought a lot at present-day Church and Lemon Streets in downtown Marietta. The Root family owned the house until 1886. In 1893 the lot was divided and the house was moved to face Lemon Street, and after Cobb Landmarks and Historical Society acquired it from Margaret and William E. Bullard in 1989, it was moved to its present location in 1990. Restored to its circa 1860 appearance, the house is accompanied by gardens based on mid-19th-century Georgia gardening practices, with ornamental, kitchen, and vegetable gardens typical of such homes. The site also includes a reproduced cookhouse built in 1996 on the original location and dimensions identified through 19th century insurance records, a smokehouse built in 2019 using reclaimed 19th century bricks after records showed one once stood on the property, a privy representing common 1860s sanitation practices in Marietta, and the Manning Cabin, a circa 1830 log cabin once occupied by members of the Manning family during the Civil War, saved from demolition in 1990 and relocated to the Root House campus in 2018.